Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758710AbZJNSlJ (ORCPT ); Wed, 14 Oct 2009 14:41:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758121AbZJNSlI (ORCPT ); Wed, 14 Oct 2009 14:41:08 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:54605 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758118AbZJNSlG (ORCPT ); Wed, 14 Oct 2009 14:41:06 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Wed, 14 Oct 2009 20:40:10 +0200 (CEST) From: Stefan Richter Subject: [PATCH 2/2] firewire: ohci: 0 may be a valid DMA address To: linux1394-devel@lists.sourceforge.net cc: linux-kernel@vger.kernel.org In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii Content-Disposition: INLINE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3261 Lines: 97 I was told that there are obscure architectures with non-coherent DMA which may DMA-map to bus address 0. We shall not use 0 as a magic number of uninitialized bus address variables. Signed-off-by: Stefan Richter --- drivers/firewire/core-transaction.c | 4 ++-- drivers/firewire/ohci.c | 9 +++++---- include/linux/firewire.h | 1 + 3 files changed, 8 insertions(+), 6 deletions(-) Index: linux-2.6.31/drivers/firewire/ohci.c =================================================================== --- linux-2.6.31.orig/drivers/firewire/ohci.c +++ linux-2.6.31/drivers/firewire/ohci.c @@ -995,7 +995,8 @@ static int at_context_queue_packet(struc packet->ack = RCODE_SEND_ERROR; return -1; } - packet->payload_bus = payload_bus; + packet->payload_bus = payload_bus; + packet->payload_mapped = true; d[2].req_count = cpu_to_le16(packet->payload_length); d[2].data_address = cpu_to_le32(payload_bus); @@ -1023,7 +1024,7 @@ static int at_context_queue_packet(struc */ if (ohci->generation != packet->generation || reg_read(ohci, OHCI1394_IntEventSet) & OHCI1394_busReset) { - if (packet->payload_length > 0) + if (packet->payload_mapped) dma_unmap_single(ohci->card.device, payload_bus, packet->payload_length, DMA_TO_DEVICE); packet->ack = RCODE_GENERATION; @@ -1059,7 +1060,7 @@ static int handle_at_packet(struct conte /* This packet was cancelled, just continue. */ return 1; - if (packet->payload_bus) + if (packet->payload_mapped) dma_unmap_single(ohci->card.device, packet->payload_bus, packet->payload_length, DMA_TO_DEVICE); @@ -1723,7 +1724,7 @@ static int ohci_cancel_packet(struct fw_ if (packet->ack != 0) goto out; - if (packet->payload_bus) + if (packet->payload_mapped) dma_unmap_single(ohci->card.device, packet->payload_bus, packet->payload_length, DMA_TO_DEVICE); Index: linux-2.6.31/drivers/firewire/core-transaction.c =================================================================== --- linux-2.6.31.orig/drivers/firewire/core-transaction.c +++ linux-2.6.31/drivers/firewire/core-transaction.c @@ -226,7 +226,7 @@ static void fw_fill_request(struct fw_pa packet->speed = speed; packet->generation = generation; packet->ack = 0; - packet->payload_bus = 0; + packet->payload_mapped = false; } /** @@ -601,7 +601,7 @@ void fw_fill_response(struct fw_packet * WARN(1, KERN_ERR "wrong tcode %d", tcode); } - response->payload_bus = 0; + response->payload_mapped = false; } EXPORT_SYMBOL(fw_fill_response); Index: linux-2.6.31/include/linux/firewire.h =================================================================== --- linux-2.6.31.orig/include/linux/firewire.h +++ linux-2.6.31/include/linux/firewire.h @@ -267,6 +267,7 @@ struct fw_packet { void *payload; size_t payload_length; dma_addr_t payload_bus; + bool payload_mapped; u32 timestamp; /* -- Stefan Richter -=====-==--= =-=- -===- http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/